Apparatus and process for producing ammonia using redundant electrical energy for pollution reduction hydrogen storage

Abstract

The application discloses a device and process for reducing pollution and storing hydrogen by utilizing redundant electric energy to produce ammonia, which comprises a reactor a and a reactor b; the reactor a is sequentially provided with a hydrogen peroxide oxidation system I, an ammonia production system II and a nitrogen fixation system III from top to bottom; the steel reactor b has the same structure as the reactor a; the top of the reactor a and the reactor b is connected with a four-way valve A; the bottom of the reactor a and the reactor b is connected with a four-way valve B; and the reactor a and the reactor b are respectively provided with a hydrogen peroxide spraying device. The whole reaction process comprises a nitrogen fixation process and an ammonia production process; the two reaction devices with the same structure are connected through the four-way valves to realize a circulating reaction, thereby continuously consuming NO and producing NH3, and achieving the double goals of reducing pollution and energy conversion. The application utilizes redundant electric energy to convert NO and synthesize NH3, improves the utilization efficiency of electric energy, simultaneously reduces the dependence on fossil fuels, and is helpful to realize sustainable utilization of energy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of energy production, and particularly relates to a device and process for reducing pollution and storing hydrogen to produce ammonia by using redundant electric energy. BACKGROUND

[0002] In the field of renewable energy, the instability of power supply often occurs due to the intermittency of power generation and transmission limitations. Hydrogen energy storage technology emerges as the times require. It converts electricity and hydrogen energy through mutual conversion, and uses excess, off-peak or low-quality electricity to produce hydrogen on a large scale, converting electric energy into hydrogen energy storage. When the power supply is insufficient, hydrogen fuel cells or other chemical reactions can be used to supplement power generation. Hydrogen fuel cells can directly convert the chemical energy of hydrogen into electric energy, avoiding energy loss in the intermediate conversion process, achieving high-efficiency power generation, and being more environmentally friendly and practical.

[0003] In addition, ammonia production and hydrogen storage technology also shows significant advantages. Ammonia has a high energy density, with a volumetric energy density of about 13.6 MJ·L -1 , which means that 1 liter of liquid ammonia contains energy equivalent to 4.5 liters of high-pressure hydrogen (35.0 MPa) or 1200 liters of normal temperature and pressure hydrogen. The liquefaction and storage cost of ammonia is relatively low, and only 1.0 MPa of pressure is required for liquefaction, which is much lower than the storage cost of liquid hydrogen. In terms of safety, the explosion limit range of ammonia is relatively narrow, and the boiling point is relatively high, which reduces the risk of fire and explosion. The irritating odor of ammonia also makes it easier to detect leaks. Finally, ammonia is easy to liquefy and store, and only needs slight pressurization at -10℃ to liquefy, with small energy loss and high safety, making it easy to store and transport. These characteristics make ammonia a very potential hydrogen storage and transportation medium. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a device and process for reducing pollution and storing hydrogen to produce ammonia by using redundant electric energy. The present application first uses hydrogenated silicon aluminum molecular sieve to catalyze hydrogen peroxide (H2O2) to effectively oxidize NO, and combines with an alkaline absorbent to achieve effective storage of nitrate, and uses Cu / Ce catalyst to promote the synthesis of ammonia (NH3). Through the catalyst process combination process, redundant electric energy is used to reduce pollution and store hydrogen to produce ammonia, providing an innovative process and method that can efficiently remove pollutants and efficiently produce ammonia.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] The utility model provides a kind of device for reducing pollution hydrogen storage ammonia with redundant electric energy, including reactor a and reactor b, reactor a is from top to bottom in turn for hydrogen peroxide oxidation system I, ammonia production system II and nitrogen fixation system III, the structure of reactor b is same with reactor a, the top of reactor a and reactor b is connected with four-way valve A, the bottom of reactor a and reactor b is connected with four-way valve B, and hydrogen peroxide spraying device is respectively arranged in reactor a and reactor b and located above hydrogen peroxide oxidation system I.

[0007] Further, the reactor a and reactor b are steel reactors, and a heating jacket is arranged outside to realize segmented heating.

[0008] Further, the catalyst type used by the hydrogen peroxide oxidation system I is a hydrogenated silicon-aluminum molecular sieve, the molecular sieve has a mesopore or macropore structure, the pore size is greater than 50 nm, and the Si / Al ratio of the catalyst is 5-30. When the silicon-aluminum molecular sieve is hydrogenated, reagents such as ammonium chloride, ammonium nitrate, and ammonium carbonate are used, and the catalyst calcination temperature is 500-600°C.

[0009] Further, the catalyst type used by the ammonia production system II is a Cu / Ce catalyst, the copper precursor is copper nitrate, copper chloride, or copper sulfate, the Cu loading is 1-10 wt%, and the carrier is CeO2.

[0010] Further, the nitrogen fixation system III uses a supported basic absorbent, wherein the basic component of the supported basic absorbent is an alkali metal oxide and an alkaline earth metal oxide, and the carrier is γ-Al2O3, SiO2, or TiO2 alone.

[0011] The utility model also provides a process for reducing pollution hydrogen storage ammonia using the device, which comprises the following steps:

[0012] (1) first, the valve port 1 and the valve port 2 of four-way valve A are communicated, the valve port 3 and the valve port 4 are communicated, the valve port 5 and the valve port 8 of four-way valve B are communicated, and the valve port 6 and the valve port 7 are communicated; then, the following (2) and (3) are performed synchronously;

[0013] (2) nitrogen fixation process: the flue gas containing a large amount of NO is introduced into reactor a through the valve port 1, and the H2O2 solution is injected into the hydrogen peroxide oxidation system I through the spraying device; the flue gas first passes through the hydrogen peroxide oxidation system I, and the hydrogenated silicon-aluminum molecular sieve is used to catalyze the oxidation of nitrogen monoxide in the flue gas by H2O2 to generate water-soluble high-valence nitrogen oxides, nitrous acid, and nitric acid; after heating, the final products in gaseous form, i.e., gaseous nitrogen oxides, gaseous nitrous acid, and gaseous nitric acid, are introduced into the ammonia production system II; in the ammonia production system II, no chemical reaction occurs, and the gas enters the nitrogen fixation system III; in the nitrogen fixation system III, the gaseous nitrogen oxides, gaseous nitrous acid, and gaseous nitric acid react with the alkali metal oxides in the basic absorbent to generate nitrate salts, which are stored, and the clean gas is discharged from the tail of the valve port 7, completing the nitrogen fixation process;

[0014] (3) Ammonia production process: the reactor b has completed the nitrogen fixation process in advance, at this time, the mixed gas containing hydrogen and water vapor is introduced into the reactor b through the valve port 5, the mixed gas first enters the nitrogen fixation system III, in which the water vapor is hydrolyzed with the stored nitrate to generate nitric acid vapor and produce alkali metal oxide, then the hydrogen gas enters the ammonia production system II together with the generated nitric acid vapor; in the ammonia production system II, the hydrogen gas reacts with the nitric acid vapor on the surface of the catalyst to produce ammonia gas, and the ammonia gas is discharged from the valve port 3 through the hydrogen peroxide oxidation system I.

[0015] Further, in the step (2) nitrogen fixation process, the concentration of NO in the flue gas is 100-20000 ppm, the gas volume of the flue gas is 1000-500000 m 3 / min, the volume space velocity is 2000-200000 h -1 , the molar ratio of H2O2 and NO is (0.1-5):1, and the concentration of the H2O2 solution is 1-5 mol / L.

[0016] In the step (2) nitrogen fixation process, the temperature of the reaction chamber of the hydrogen peroxide oxidation system I is 100-250℃.

[0017] In the step (3) ammonia production process, the volume concentration of H2 in the mixed gas containing hydrogen and water vapor is 1%-10%, the volume concentration of water vapor is 1%-5%, and the rest is N2, the gas volume of the mixed gas is 100-500000 m 3 / min, and the volume space velocity is 2000-200000 h -1 .

[0018] Further, in the step (3) ammonia production process, the reaction temperature of the nitrogen fixation system III is 100-300℃.

[0019] Further, in the step (3) ammonia production process, the reaction temperature of the ammonia production system II is 150-250℃.

[0020] It should be noted that the reactor a and the reactor b are heated by redundant electric energy, and the H2 introduced in the step (3) ammonia production process is obtained by electrolyzing water by the redundant electric energy. Since the reactor a and the reactor b can be segmented and heated, the ammonia production system II does not need to be heated in the above-mentioned step (2) nitrogen fixation process, and the hydrogen peroxide oxidation system I does not need to be heated in the above-mentioned step (3) ammonia production process.

[0021] Compared with the prior art, the device and process of the present application have the following beneficial effects:

[0022] 1. The entire reaction process is connected by a four-way valve to two reaction devices of the same structure, realizes a circulating reaction, continuously consumes NO and produces NH3, and realizes the dual goals of pollution reduction and energy conversion.

[0023] 2. Using redundant electricity to convert NO and synthesize NH3 improves the efficiency of electricity utilization, while reducing dependence on fossil fuels and contributing to the sustainable use of energy.

[0024] 3. The process can be adjusted according to the actual situation of power supply and NO emissions. It has good flexibility and adaptability and is suitable for different industrial environments and energy management needs.

[0025] 4. The catalysis of H2O2 by hydrogenated silicon aluminum molecular sieve and Cu / Ce catalyst improved the NO conversion rate and NH3 synthesis efficiency, demonstrating the innovative application of technology in the field of chemical engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic diagram of the structure of a hydrogen storage and ammonia production device that uses redundant electricity to reduce pollution.

[0028] Figure 2 Schematic diagram of the cyclic reaction process of hydrogen storage and ammonia production using redundant electricity to reduce pollution.

[0029] Figure 3 NO oxidation efficiency of H-SM-5 at different hydrogen peroxide concentrations. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to specific examples. It should be understood that the following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention, and that those skilled in the art may make non-essential improvements and adjustments based on the contents of the above invention.

[0031] Example 1

[0032] Figure 1 This is a schematic diagram of a hydrogen storage and ammonia production device that utilizes redundant electrical energy for pollution reduction. The device consists of two identical steel reactors, labeled a and b, interconnected by a four-way valve to enable a cyclic reaction. This design allows two processes—nitrogen fixation and ammonia production—to proceed simultaneously. The detailed structure is as follows:

[0033] The device for reducing pollution and storing hydrogen to produce ammonia by using redundant electric energy comprises a reactor a and a reactor b. The reactor a is sequentially provided with a hydrogen peroxide oxidation system I, an ammonia production system II and a nitrogen fixation system III from top to bottom. The reactor b has the same structure as the reactor a. The top of the reactor a and the reactor b is connected with a four-way valve A, and the bottom of the reactor a and the reactor b is connected with a four-way valve B. The reactor a and the reactor b are respectively provided with a hydrogen peroxide spraying device. Preferably, the reactor a and the reactor b are steel reactors, and are externally provided with heating jackets to realize segmented heating.

[0034] The catalyst type used in the hydrogen peroxide oxidation system I is a hydrogenated silicon-aluminum molecular sieve. The molecular sieve has a mesopore or macropore structure, a pore size greater than 50 nm, and a catalyst Si / Al of 5-30. When the silicon-aluminum molecular sieve is treated by hydrogenation, reagents such as ammonium chloride, ammonium nitrate and ammonium carbonate are used. The catalyst calcination temperature is 500-600°C. The catalyst type used in the ammonia production system II is a Cu / Ce catalyst. The copper precursor is copper nitrate, copper chloride or copper sulfate. The Cu loading is 1-10wt%. The carrier type is CeO2. The alkali absorbent used in the nitrogen fixation system III has a basic component of K, Na or Ca, and a carrier type of γ-Al2O3, SiO2 or TiO2.

[0035] Example 2

[0036] The device described in Example 1 is used to carry out the process of reducing pollution and storing hydrogen to produce ammonia. The process is as follows:

[0037] (1) First, the valve port 1 and the valve port 2 of the four-way valve A are communicated, the valve port 3 and the valve port 4 are communicated, the valve port 5 and the valve port 8 of the four-way valve B are communicated, and the valve port 6 and the valve port 7 are communicated. Then, the following (2) and (3) are carried out synchronously.

[0038] (2) Nitrogen fixation process: gas flow is 1000m 3 / min, volume space velocity is 12000h -1 / min, and contains 2000ppm NO. The flue gas is introduced into the steel reactor a through the valve port 1. The flue gas is introduced into the reactor a through the valve port 1. The flue gas first passes through the hydrogen peroxide oxidation system I. The molar ratio of H2O2 to NO is 1:1. The concentration of the H2O2 solution is 4mol / L. The reaction chamber temperature is 200°C. The hydrogenated silicon-aluminum molecular sieve H-ZSM-5 is used to catalyze the oxidation of nitrogen monoxide in the flue gas by hydrogen peroxide to generate water-soluble high-valence nitrogen oxides, nitrous acid and nitric acid. After heating, the final product is in the form of gas, i.e. gaseous nitrogen oxides, gaseous nitrous acid and gaseous nitric acid, which is introduced into the ammonia production system II.

[0039] In the ammonia production system II, no chemical reaction occurs. The gas enters the nitrogen fixation system III.

[0040] In the nitrogen fixation system III, gaseous nitrogen oxides, gaseous nitrous acid and gaseous nitric acid react with alkali metal oxides in the basic absorbent K2O / γ-Al2O3 to form nitrate salts for storage, and clean gas is discharged from the tail of valve 7 to complete the nitrogen fixation process.

[0041] (3) Ammonia production process: the mixed gas containing hydrogen and water vapor is introduced into reactor b (reactor b has completed the nitrogen fixation process in advance, as described in step (2) above) through valve port 5, and the mixed gas (10% hydrogen by volume and 3% water vapor by volume, with the remainder being nitrogen) is reacted at a temperature of 250°C and a pressure of 1.0 MPa, a flow rate of 1000 ml / min, a volume space velocity of 6000 h-1, and a hydrogen concentration of 10% by volume, to produce ammonia gas. 3 -1 First, the hydrogen gas enters the nitrogen fixation system III, where the water vapor reacts with the stored nitrate salts at 250°C to produce nitric acid vapor and generate alkali metal oxides. Subsequently, the hydrogen gas enters the ammonia production system II together with the generated nitric acid vapor.

[0042] In the ammonia production system II, under normal pressure, the hydrogen gas with a volume concentration of 10% reacts with the nitric acid vapor at 200°C in the presence of a Cu / Ce catalyst to produce ammonia gas, which is discharged through the hydrogen peroxide oxidation system I and valve port 3, thereby completing the ammonia production process.

[0043] After steps (2) and (3) are completed, valve port 1 of four-way valve A is connected to valve port 4, valve port 2 is connected to valve port 3, valve port 5 of four-way valve B is connected to valve port 6, and valve port 7 is connected to valve port 8. Steps (2) and (3) are simultaneously performed in reactor b for the nitrogen fixation process and in reactor a for the ammonia production process, thereby achieving a cyclic reaction (as shown in FIG. 1) through the control of the four-way valves. Figure 2

[0044] The laboratory preparation process of the hydrogenated silicoalumina molecular sieve H-ZSM-5 includes the following steps:

[0045] Ion exchange is performed using 30 ml of 1.0 mol / L NH4Cl aqueous solution at 60°C for 2 hours (repeated three times), the sample is filtered and washed with distilled water, the residue is dried at 110°C for 12 hours, and then calcined at 600°C for 1 hour to obtain H-ZSM-5. The efficiency of the H-ZSM-5 in oxidizing NO with H2O2 solution is as shown in FIG. 2. Figure 3

[0046] The laboratory preparation process of the basic absorbent K2O / γ-Al2O3 includes the following steps:

[0047] ​​​The 1 g of finished γ-Al2O3 support was calcined at 550 °C for 2 h, after which 5 g of KNO3 was accurately weighed and dissolved in 30 ml of deionized water to prepare the impregnation solution with the desired concentration. K was loaded on the γ-Al2O3 support using the wet impregnation method. After drying at 80 °C and calcination at a temperature of 550 °C, the resulting catalyst was designated as K2O / γ-Al2O3.

[0048] The laboratory preparation process of the Cu / Ce catalyst includes the following steps:

[0049] 10 g of Ce(NO3)3-6H2O was dissolved in 30 ml of deionized water and stirred until completely dissolved. Then 30 ml of concentrated ammonia was added, and the precipitate was stirred. After aging at room temperature for 3 h, the precipitate was washed several times with deionized water to pH = 7. Finally, the precipitate was dried at 80 °C for 10 h, and then calcined in a muffle furnace at 550 °C for 2 h. It was labeled as CeO2-OH. Using the wet impregnation method, 0.78 g of copper nitrate was weighed and prepared into a solution as a precursor to load Cu on the CeO2 support. After drying at 80 °C and calcination at 550 °C, the resulting catalyst was designated as Cu / Ce.

[0050] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A device for reducing pollution by storing hydrogen and producing ammonia using redundant electrical energy, characterized in that: The invention comprises a reactor a and a reactor b. The reactor a comprises a hydrogen peroxide oxidation system I, an ammonia production system II and a nitrogen fixation system III from top to bottom. The structure of the steel reactor b is the same as that of the reactor a. The tops of the reactors a and b are connected with a four-way valve A, and the bottoms of the reactors a and b are connected with a four-way valve B. The reactors a and b are respectively provided with a hydrogen peroxide spraying device.

2. The device for reducing pollution by storing hydrogen and producing ammonia using redundant electric energy according to claim 1, characterized in that: The catalyst type used in hydrogen peroxide oxidation system I is hydride silicon aluminum molecular sieve, the molecular sieve has a medium or large pore structure, the pore size is greater than 50nm, and the catalyst Si / Al is 5-30.

3. The device for reducing pollution by storing hydrogen and producing ammonia using redundant electric energy according to claim 1, characterized in that: The catalyst type used in the ammonia production system II is a Cu / Ce catalyst, the copper precursors are copper nitrate, copper chloride, and copper sulfate, the Cu loading is 1-10wt%, and the carrier is CeO2.

4. The device for reducing pollution by storing hydrogen and producing ammonia using redundant electric energy according to claim 1, characterized in that: Nitrogen fixation system III uses a supported alkaline absorbent, wherein the alkaline components are alkali metal oxides and alkaline earth metal oxides, and the carrier is a single γ-Al2O3, SiO2 or TiO2.

5. A process for producing ammonia by storing hydrogen with pollution reduction using the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) First, connect valve port 1 of four-way valve A to valve port 2, and valve port 3 to valve port 4; connect valve port 5 of four-way valve B to valve port 8, and valve port 6 to valve port 7; then simultaneously carry out the following (2) and (3); (2) Nitrogen fixation process: Flue gas containing a large amount of NO is introduced into reactor a through valve port 1, and H2O2 solution is injected into hydrogen peroxide oxidation system I through a spray device. Flue gas first passes through hydrogen peroxide oxidation system I, where H2O2 is catalyzed by hydridosilicon aluminum molecular sieve to oxidize nitrogen monoxide in the flue gas to generate water-soluble high-valent nitrogen oxides, nitrous acid, and nitric acid. After heating, the flue gas is finally introduced into ammonia production system II in the form of gaseous nitrogen oxides, gaseous nitrous acid, and gaseous nitric acid. In ammonia production system II, no chemical reaction occurs, and the gas enters nitrogen fixation system III. In nitrogen fixation system III, gaseous nitrogen oxides, gaseous nitrous acid, and gaseous nitric acid react with alkali metal oxides in the alkaline absorbent to generate nitrates, which are stored. Clean gas is discharged from the tail of valve port 7, completing the nitrogen fixation process. (3) Ammonia production process: Reactor b has completed the nitrogen fixation process in advance. At this time, a gas mixture containing hydrogen and water vapor enters reactor b through valve port 5. The gas mixture first enters nitrogen fixation system III, where water vapor and stored nitrate are hydrolyzed to produce nitric acid vapor and generate alkali metal oxides. Subsequently, hydrogen and the generated nitric acid vapor enter ammonia production system II together; in the ammonia production system II, hydrogen and nitric acid vapor react on the catalyst surface to produce ammonia, which is discharged from valve port 3 through hydrogen peroxide oxidation system I.

6. The process according to claim 5, characterized in that During the nitrogen fixation process in step (2), the NO concentration in the flue gas is 100-20000 ppm, and the flue gas volume is 1000-500000 m 3 / min, volume space velocity is 2000-200000h -1 , the molar ratio of H2O2 and NO is (0.1-5):1, and the concentration of H2O2 solution is 1-5mol / L.

7. The process according to claim 5, characterized in that During the nitrogen fixation process in step (2), the temperature of the reaction chamber of the hydrogen peroxide oxidation system I is 100-250°C.

8. The process according to claim 5, characterized in that In the ammonia production process of step (3), the volume concentration of H2 in the mixed gas containing hydrogen and water vapor is 1%-10%, the volume concentration of water vapor is 1%-5%, and the rest is N2. The gas volume of the mixed gas is 100-500000m 3 / min, volume space velocity is 2000-200000h -1 .

9. The process according to claim 5, characterized in that During the ammonia production process in step (3), the reaction temperature of the nitrogen fixation system III is 100-300°C.

10. The process according to claim 5, characterized in that During the ammonia production process in step (3), the reaction temperature of the ammonia production system II is 150-250°C.

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